Gas burner

ABSTRACT

A gas burner including a mounting plate and a burner cap is provided with a baffle for distributing the flow of gas from an inlet in the plate to burner ports in the cap for preventing uneven flame distribution and flame extinction. The baffle includes a central opening surrounded by an inclined wall in which are formed a group of uniformly spaced trapezoidal slots.

United Stat eSP atent 1 1 Mizerak et a1.

1111' "3,858,811 1451 Jan. 7, 1.975

[54] GAS BURNER 979,734 12/1910 Beler 239/553 Inventors: Dennis S.Mizerak, Cicero; Charles 3,738,577 6/1973 Blanzy et a1 239/4255 m-Hickory m both FOREIGN PATENTS OR APPLICATIONS Of [11. i 19,061 0/1900Great Britain................... 239/5533 1,178,993 12/1958 F 239/5533[731 Asslgnee: f Cmnpany) Hlnsdale 15,445 9/1952 0:112:11 239/5533 22Filed; J 2 1973 Primary ExaminerCarroll B. D ority, Jr.

Attorney, Agent, or Firm-Mason, Kolehmainen, [21] Appl. No.: 375,769Rathbm-n & w

[52] US. Cl. 239/553.3, 239/567, 48/180 B ABSTRACT [51] Int. Cl B05b1/14 A gas burner including a mounting plate and a burner [58] Field ofSearch 431/354; 239/553.3, 568, cap is provided witha baffle fordistributing the flow 239/553, 590.3, 569; 48/180 R, 180 B, 180 of gasfrom an inlet in the plate to burner ports in the C, 180 M cap forpreventing uneven flame distribution and flame extinction. The baffleincludes a central opening [56] References Cited surrounded by aninclined wall in which are formed a UN T D STATES PATENTS group ofuniformly spaced trapezoidal slots. 407,291 7/ I889 Hamilton 431/354 11Claims, 4 Drawing Figures 52 5O D 0 0 7 l6 /,Z 58 A 1\ J I l l l l I I II k 7 4O 36 18 so 46 I 26 34 GAS BURNER This invention relates to gasburner devices such as are used in home cooking ranges and recreationalvehicle ranges. More particularly, this invention relates to gasdistribution apparatus or baffles which can be used to distribute gasuniformly into a gas burner chamber for uniform distribution to the gasburner ports.

Home gas ranges and recreational vehicle (RV) gas ranges have one ormore gas burners capable of providing a flame for heating a cookingutensil. The gas burner generally comprises an enclosed chamber having agas inlet and a gas outlet. The outlet generally comprises one or moreapertures called burner ports. A mixture of a combustible gas andprimary air enters the burner chamber from an inlet tube generallycalled a mixing tube and the mixture of gases is ignited to provideflame at the burner ports. The air around the burner ports, calledsecondary air, supplements the primary air to provide enough oxygen forcombustion at the burner ports.

To evenly heat a cooking utensil, it is necessary to provide gasuniformly to each burner port. At moderate gas flow rates uniform gasdistribution is not a significant problem. However, at low and highrates, the gas flow characteristics through a burner cause twosubstantial problems: (1) flame extinction, and (2) non-uniform gasdistribution to burner ports. These problems are aggravated in a burnerhaving an off center gas inlet. The burner of the present inventioncontains a baffle or gas distributing means which can be easily insertedinto a gas burner during manufacture for distributing gas uniformly tothe burner ports to overcome the difficulties of flame extinction andnon uniform gas flow.

The baffle of the present invention is most useful in a burner which hasan off-center gas inlet. Burners having a center hole for supplyingsecondary air are sometimes adapted to receive a top burner thermostatand thus have off-center gas inlets. As a result of the offcenter inlet,the burner ports closest to the gas inlet may receive more gas thanthose farther away from the gas inlet. The resulting flame distributionis not uniform.

One attempt to solve this gas distribution problem has been to provideadditional gas burner structure such as a post or protrusion fordirecting the gas in the desired direction. This approach isinappropriate in some types of burner due to added expense in manufacture of the burner and because of lack of uniform distribution over awide range of flow rates. Another approach has been to use a bafflehaving only a central aperture in an attempt to direct the gas centrallyupward as would result from a central gas inlet. Such a baffle doesprovide uniform gas distribution, but presents excessive restriction toflow at low flow rates.

Another proposal has been a baffle which provides different sized holespositioned at different locations around the baffle. Smaller slots areprovided at areas of higher gas pressure in an attempt to pass an equalamount of gas through the baffle at each slot. These baffles, however,are prohibitively expensive to manufacture and must be speciallydesigned for each particular burner. In addition, this type of bafflemust be installed in a specific orientation in the burner, and this addsto the expense of manufacture.

A primary object of the present invention is to provide a gas burnerhaving a uniform gas flow through the burner ports for the entireoperating range of gas burner flow rates.

Further objects of the present invention are to provide a gas burnerhaving the following characteristics: uniform distribution of gas to theburner ports even when the gas burner inlet is off-center; upward flameangle rather than a horizontal or downward angled flame; and a gasburner baffle having ports capable of distributing gas uniformly at allflow rates. other ob jects are to provide an improved baffle for gasburners which can be manufactured economically of inexpensive materialand can be easily and economically mounted in a gas burner.

In brief, the above and other objects and advantages of the presentinvention are achieved through the provision of a gas burner including amounting plate, a burner cap, and a baffle of novel configuration. Themounting plate includes a gas inlet, which may be located in anoff-center position. The burner cap includes a group of burner ports,and a burner chamber, defined between the plate and cap, communicateswith the inlet and the ports.

In accordance with the invention the baffle includes a central openingsurrounding a group of additional openings. The baffle is symmetricalabout its center and is formed from thin sheet material so that theexpense of making the baffle and of positioning it in the burner isminimized. An inclined wall extends from adjacent the outer edge of thebaffle and surrounds the central opening. The additional openings are inthe form of trapezoidal slots in the inclined wall.

The invention together with the above and other ob jects and advantagesmay be best understood from consideration of the following detaileddescription of an illustrative embodiment of the invention shown in theaccompanying drawings, wherein:

FIG. 1 is a side elevational view of a gas burner con structed inaccordance with the present invention, illustrating the burner inconjunction with a mixer tube and mounting bracket;

FIG. 2 is an enlarged cross sectional view of the gas burner;

FIG. 3 is an enlarged plan view of the baffle of the gas burner; and

FIG. 4 is a cross sectional view, on a reduced scale, of the baffletaken along line 4-4 of FIG. 3.

Referring now to the drawings, and initially to FIGS. l and 2, there isillustrated a gas burner, generally designated by the reference numeralIll and embodying the features of the present invention. The burner issup plied with fuel by a gas mixing tube 12 and is mounted in a range(not shown) by a support bracket or clamp 14. In general, burner 10includes a burner cap 16 mounted on a mounting plate 18 to provide anenclosed burner chamber 20. The cap 16 has a plurality of gas burnerports 22 which serve as a gas outlet for gas to be ignited. Inaccordance with an important feature of the present invention, a baffle24 is supported within the chamber 20 between a gas inlet opening 26 inthe plate 18 and the gas outlet ports 22 in order to prevent unevenflame distribution and flame extinction at ports 22. The ports 22 areuniformly arranged about the burner chamber 20.

Referring more particularly to FIG. 1, gas entering mixing tube 12 froma suitable source (not shown) passes through a venturi portion 28 of themixing tube and primary air enters a primary air inlet 30 and mixes withthe gas. The combustible mixture of gas and primary air enters thechamber 20 through the mounting plate inlet 26. The mixture then passesthrough the baffle 24 and is expelled through the gas discharge ports22. Secondary air is entrained in the mixture at this region, and afterignition a cooking flame exists in the vicinity of ports 22.

With reference more particularly to the structure of the burner as bestillustrated in FIG. 2, the mounting plate 18 comprises a one-piecestamped structure having a central circular cylindrical wall 32 and aneccentric collar 34 defining the gas inlet 26 and serving tointerconnect the plate 18 and the mixing tube 12. An outer circular rim36 of the plate 18 facilitates joining of the plate with the burner cap16.

Cap 16 includes an outer wall 38 terminating at its lower edge in aflange portion 40 crimped to the rim 36 of plate 18 an inner wall 42 ofthe cap 16 includes a circular cylindrical portion 44 interfitting withwall 32 of plate 18 to define a central vertical passageway 46 throughburner 10. As will be understood by those skilled in the art, the passge46 may provide a passage for secondary air to reach the top of theburner, and may also accommodate a top burner thermostat if desired. Apair of ledges 48 and 50 define a flame retention region 52 surroundingports 22 at the outer and upper rim portion of the burner.

In the use of known gas burners problems have been encountered inobtaining flame retention and uniformity at various gas flow rates. Thisproblem has been particularly acute with burners having an eccentricinlet. At high rates of gas flow, the differential in pressure existingaround the burner port area results in uneven flame due to differentangles of gas emission from ports at different locations. To overcomethis problem, baffles or flow restrictors have been used. However, withknown devices the restriction to flow is too great and flame extinctionoccurs at low rates of flow.

In accordance with the present invention, the baffle 24 is provided toovercome these problems. At high flow rates the baffle 24 provides evenflame distribution around the full extent of the ports 22. At low ratesof flow the baffle 24 offers only small resistance to flow and theproblem of undesirable flame extinction is minimized.

Proceeding now to a description of the baffle 24, the baffle 24 ispreferably formed as by stamping from a thin sheet of material so thatthe expense of making the baffle is minimized. In addition, the baffleis symmetrical about its center, and since no keying or positioning ofthe baffle in the burner 10 is necessary, the expense of fabricating theburner is reduced. In general, the baffle 24 has a central aperture 54surrounded by a plurality of additional openings 56 placed symmetricallyaround the central opening 54. As best shown in FIG. 3, the centralopening 54 has an area substantially larger than the area of any oneslot 56. The gas inlet 26 is not aligned with central opening 54.

More specifically, the baffle 24 includes a circular outer rim portion58 permitting the baffle to be clamped in position between the burnercap 16 and the plate 18 when the burner is assembled. An inclined wall60 extends inwardly and upwardly from the rim 58, and the inner edge ofwall 60 defines the central opening 54 which is preferably circular.Each outer opening 56 is located in the inclined wall 60 and varies inwidth from a maximum width adjacent the opening 54 to a minimum widthadjacent the rim 58. Preferably the openings 56 are trapezoidal andinclude parallel top and bottom edges.

In the use of the baffle 24, all of the gas flowing into the burner 10passes through the openings 54 and 56 of the baffle before reaching theoutlet ports 22. At relatively high flow rates, a substantial portion ofthe gas tends to be directed by the inclined wall 60 toward and throughthe central opening 54 resulting in uniform distribution of gas to theports 22. If only the opening 54 were provided, performance at high flowrates would be satisfactory, but at low flow rates excessive restrictionwould be present. The additional openings 56 reduce the restriction atlow flow rates, but at high rates do not permit a substantial portion ofthe gas to bypass the central opening 54. It is believed that thisresults from the slope of the wall 60, preferably between l5 and fromhorizontal, and from the varying width of the outer openings 56.

At low flow rates, the influence of the inlined wall 60 upon thedirection of flow through the baffle 24 is reduced, and a substantialportion of the flow passes through the outer openings 56. The total areaof the openings 54 and 56 is large enough so that the restriction toflow is small and the pressure drop across the baffle 24 is also small.Thus, ample gas reaches the ports 22 reliably to support combustion, andflame extinction is avoided.

Although the present invention has been described with reference todetails of the illustrated embodiment, such details are not intended tolimit the scope of the invention as defined in the following claims.

What is claimed and desired to be secured by Letters Patent of theUnited States is:

1. In a gas burner, a burner chamber including uniformly arranged outletmeans about the chamber, and a gas inlet, the improvement comprisingbaffle means mounted within said burner chamber and positioned betweensaid gas inlet and said burner ports, said baffle means being inclinedupwardly and inwardly toward a central opening for the passage of gastherethrough and having a plurality of uniformly spaced baffle slots ofuniform configuration surrounding said central opening and extendingtoward said opening, said gas inlet being non-aligned with said centralopening and said central opening having an area substantially largerthan the area of any one baffle slot.

2. The combination of claim 1 wherein the baffle means comprises aformed sheet of thin material.

3. The combination of claim 2, further comprising a rim extendingradially from the base of the inclined annular wall for seating thebaffle in position within the burner chamber.

4. The combination of claim 3 wherein the baffle slots increase in widthtoward the center of the baffle.

5. The combination of claim 4 wherein the baffle slots are trapezoidallyshaped.

6. The combination of claim 5 wherein the parallel sides of thetrapezoidally shaped slots are substantially parallel to said rim andwherein the parallel side closer to said rim is shorter than theparallel side closer to said central opening.

7. A gas burner comprising in combination a mounting plate having a gasinlet therein and having a generally circular outer plate edge;

a cap having a generally circular outer cap edge attached to said plateedge and having uniformly arranged outlet means therein;

said plate and cap being constructed and arranged to enclose a burnerchamber therebetween communicating with said inlet and said burnerports;

a baffle supported between said cap and plate for distributing the flowof gas from said gas inlet through said chamber to said burner ports;

said baffle being upwardly and inwardly inclined and symmetrical aboutits center and including a central opening for the passage of gastherethrough and a plurality of of uniform configuration surroundingsaid central opening and extending toward said opening, said centralopening having an 5 center of said mounting plate.

9. The gas burner of claim 7, said baffle including a generally circularouter edge sandwiched between said plate edge and said cap edge.

10. The gas burner of claim 7, said central opening 10 being defined bythe inner edge of said inclined portion.

11. The gas burner of claim 10, each slot being of varying width andhaving its widest portion closest to the center of said baffle.

1. In a gas burner, a burner chamber including uniformly arranged outletmeans about the chamber, and a gas inlet, the improvement comprisingbaffle means mounted within said burner chamber and positioned betweensaid gas inlet and said burner ports, said baffle means being inclinedupwardly and inwardly toward a central opening for the passage of gastherethrough and having a plurality of uniformly spaced baffle slots ofuniform configuration surrounding said central opening and extendingtoward said opening, said gas inlet being non-aligned with said centralopening and said central opening having an area substantially largerthan the area of any one baffle slot.
 2. The combination of claim 1wherein the baffle means comprises a formed sheet of thin material. 3.The combination of claim 2, further comprising a rim extending radiallyfrom the base of the inclined annular wall for seating the baffle inposition within the burner chamber.
 4. The combination of claim 3wherein the baffle slots increase in width toward the center of thebaffle.
 5. The combination of claim 4 wherein the baffle slots aretrapezoidally shaped.
 6. The combination of claim 5 wherein the parallelsides of the trapezoidally shaped slots are substantially parallel tosaid rim and wherein the parallel side closer to said rim is shorterthan the parallel side closer to said central opening.
 7. A gas burnercomprising in combination a mounting plate having a gas inlet thereinand having a generally circular outer plate edge; a cap having agenerally circular outer cap edge attached to said plate edge and havinguniformly arranged outlet means therein; said plate and cap beingconstructed and arranged to enclose a burner chamber therebetweencommunicating with said inlet and said burner ports; a baffle supportedbetween said cap and plate for distributing the flow of gas from saidgas inlet through said chamber to said burner ports; said baffle beingupwardly and inwardly inclined and symmetrical about its center andincluding a central opening for the passage of gas therethrough and aplurality of of uniform configuration surrounding said central openingand extending toward said opening, said central opening having an areasubstantially greater than the area of any one additional opening, andsaid gas inlet being non-aligned with said central opening.
 8. The gasburner of claim 7, said inlet being off-center of said mounting plate.9. The gas burner of claim 7, said baffle including a generally circularouter edge sandwiched between said plate edge and said cap edge.
 10. Thegas burner of claim 7, said central opening being defined by the inneredge of said inclined portion.
 11. The gas burner of claim 10, each slotbeing of varying width and having its widest portion closest to thecenter of said baffle.